A luxury limo, Italian-style. With its all-new four-door, Maserati aims to challenge Audi, BMW, Mercedes-Benz and Jaguar. The sixth-generation Quattroporte is larger, lighter, faster, more powerful and more fuel efficient than the almost decade-old model it replaces. According to Maserati, it's now a valid competitor to long-wheelbase versions of the A8, 7-series, S-class and XJ. Numbers support what the suits say; axle-to-axle, the one-size-fits-all Maserati measures nearly 125 inches; nose-to-tail is a journey of more than 17 feet. It's a biggie.

The Quattroporte is also the first installment in Maserati's ambitious expansion plan. The objective is to lift annual global sales from around 6,000 today to 50,000 by 2015. While initially, the Quattroporte is to be offered only with the company's new 523-hp V8 engine and in rear-drive, 404-hp V6 versions with rear-drive or all-wheel drive, will be available in Europe around the middle of next year.

The same V6 drivetrains will power the new Ghibli, a smaller-than-Quattroporte sedan due to launch in Europe in 2013. Later, an SUV named Levante will be added to the brand's lineup. Together, these two models are expected to account for the bulk -- around 40,000 -- of the 2015 sales target, according to brand boss Harald Wester.

With the new Quattroporte's spaciousness, criticisms of its predecessor's cramped rear seat are firmly in the past. Wester believes that the all-wheel-drive variant has the potential to sell at a rate of up to 15,000 a year, aided by significant growth planned for the brand's global retail network.

Like a bulky businessman in a cunningly tailored suit, the Quattroporte hides its size well. A crisp crease running from front fender to tail-light cluster disguises its length and emphasizes the shape's broad shoulders. Large headlights and a tautly drawn grille with vertical bars and the trident emblem give the new Quattroporte a more handsome visage. Only from the rear, where the large trunk forced the designers to use every trick in their books to make it seem smaller, does the Maserati appear anything less than elegant.

Although most of the Quattroporte body's strength is derived from a central steel structure, many of the exterior panels -- hood, front fenders, doors and trunk lid -- are aluminum. That accounts for much of the almost 200-pound weight reduction compared to the outgoing model.

Improved aerodynamics -- both drag and lift have been cut -- help the Quattroporte V8 to a (claimed) 190-mph top speed, making it easily the brand's fastest-ever four-door. Although designed by Maserati, the V8 engine is manufactured by Ferrari, fellow Fiat Group company, at Maranello. The 3.8-liter direct-injection 90-degree unit is equipped with a pair of twin-scroll turbochargers. It's a revver, producing its 523 hp at 6800 rpm on the way to a 7200-rpm cutout. While maximum torque is 479 lb-ft between 2000 and 4000 rpm, invoking the overboost function (available in normal and sport modes) increases this to 524 lb-ft between 2,250 and 3,500rpm. Both V8 and V6 versions of the Quattroporte use ZF's excellent eight-speed automatic.

Inside, Maserati's designers have aimed for simplicity to go with the new Quattroporte's spaciousness. Behind the three-spoke steering wheel is a pair of traditional dials, flanking an LCD display. The center stack is dominated by an 8.4-inch touchscreen display, which is situated above an easy-to-use array of heating and ventilation controls. Leather and wood are employed. Slabs of tree divide the upper and lower sections of the instrument panel. There's no fussiness to the design of the seat coverings or door trims.

The Quattroporte will offer two interior configurations. The car was presented to international media (ahead of its public debut in Detroit in January) with a five-seat interior, which permits a 60/40 split-fold backrest for those who appreciate some load-carrying versatility in their limousine. The more luxurious four-seat layout will lack this feature.

What is it like to drive?

For a limo, the Maserati is a mighty engaging car. There's a surprising amount of road feel through the Quattroporte's three-spoke wheel, and the car's 50/50 weight distribution, standard 20-inch tires and variable Skyhook damping system endow it with excellent cornering grip and balance. It's a big car that's readier than most to accommodate a driver running late for an appointment on the other side of a mountain pass.

The new twin-turbo V8 is superb. The throttle pedal delivers near-instant gratification, and once the exhaust fully opens its throat (above 4,200 rpm in normal mode), this engine sings. The 3.8-liter's delivery is hard to fault. There's ample torque anywhere on the tach dial, and the Quattroporte is seriously thrusty when given wide-open throttle. Flat-to-the-floor auto upshifts weren't as seamless or smooth as they should have been, but the V8s at the launch were pre-production cars rather than the finished article. According to Maserati's vehicle integration and validation manager, Benedetto Orvietani, calibration work on the drivetrain was “95 percent” complete. This problem should be solved by the time production cars begin rolling off the brand's new assembly line in Torino early next year.

Ride quality is on the firm side for a luxury car, even in normal mode. For the media introduction, Maserati chose the Cote d'Azur. The roads inland of Nice and Cannes aren't the best in the world, but neither are they the worst. The big sedan would occasionally fail to smother the sharpest of small impacts -- poorly aligned road joins, for example -- as well as a limousine should. On the French autoroute comfort was excellent; the ride smoothed out and that great V8 could be faintly heard. It's not likely to be used this way, but the Quattroporte is a car that feels like it would make a fine transcontinental tourer. It's quite serene halfway to its top speed (which we didn't get anywhere near on the crowded and heavily policed roads of southern France.)

Selecting sport mode firms the Quattroporte's suspension and steering, makes the engine and transmission more responsive, holds open the exhaust system's valves throughout the rev range to give gases the shortest escape route and makes using the pretty paddle shifters practically irresistible. The increase in exhaust volume is only moderate, but the Maserati's driving character is transformed. In this mode it's amazingly agile and eager for a 4000-pound-plus luxury machine. A third mode, labeled ICE (for Increased Control Efficiency) is also available. It dulls throttle response, shifts up earlier and more softly, and keeps the exhaust valves closed until 5,000 rpm to improve fuel efficiency.

From the rear seat -- yes, of course we tried it, forcing another motoring writer to play chauffer -- the legroom afforded by the new model's increased wheelbase is ample. While seat comfort back there is excellent, headroom isn't as generous as it could be. Although the rear-seat furnishings are plain, it's a warmer environment than the clinical coolness favored by the German brands.

Do I want it?

Maybe. The Quattroporte V8 isn't a car for every successful entrepreneur or executive. But it has appeal for those who like their luxury characterful, quick and a little quirky -- or, to put it plainly, un-German. Maserati's enlarged limo is now properly spacious, with a distinctly Italian aesthetic inside and out. It's also a much more engaging and entertaining drive, offering a degree of involvement and satisfaction at some cost to ultimate comfort.

2013 MASERATI QUATTROPORTE

ON SALE: July 2013

BASE PRICE: $135,000 (Estimated: European prices will apparently be similar to current QP with 4.7 V8, so the same should be true for the U.S. market, yes?)